Categorization of near-term mouse fetuses according to their viability as a tool for developmental toxicity screening.
In 1,015 CD-1 near-term mouse fetuses, removed by cesarean section after cervical dislocation of dams, skin color, motility, crying, and breathing were studied. Three categories of fetuses were considered: living and surviving (92.5%); living but non-surviving (6.9%), and stillborn (0.6%). Particular attention was paid to the following: 24 fetuses, still apneic after routine manipulation, started breathing by specific maneuvers; 5 of these 24 fetuses were apparently dead when apnea recovery was successfully tried, and the living but non-surviving category must be considered in developmental toxicity screening as prenatal injuries may be manifested by an increase in the incidence of the fetuses belonging to this category.
Pinto-Machado
J
J
Institute of Anatomy, Faculty of Medicine, University of Oporto, Portugal.
D000818:Animals; D000831:Animals, Newborn / Q000145:classification*; D005328:Fetal Viability / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D012151:Resuscitation; D014116:Toxicology / Q000379:methods*